Phase change inks (sometimes referred to as “solid inks” and “hot melt inks”) have been used in various liquid deposition techniques. Phase change inks often contain a “phase-change agent” that enables the ink to exist in a solid phase at ambient temperatures, but also exist in the liquid phase at the elevated operating temperature of an ink jet printing device. At the deposit operating temperature, droplets of liquid ink are ejected from the printing device and, as the ink is jetted towards or contacts the surface of the recording substrate, either directly or via an intermediate heated transfer belt or drum, the ink rapidly solidifies onto the substrate to form a predetermined pattern of solidified ink marks. Phase change inks have also been used in other printing technologies, such as gravure printing, as disclosed in, for example, U.S. Pat. No. 5,496,879, the entire disclosure of which is totally incorporated herein by reference. Phase change inks have also been used for applications such as postal marking, industrial marking, and labeling.
Phase change inks are desirable for ink jet printers because they remain in a solid phase at room temperature, which is convenient during shipping and ink handling, enables long term storage, and ease of use. In addition, the problems associated with nozzle clogging as a result of ink evaporation with liquid ink jet inks are largely eliminated, thereby greatly improving the reliability of the ink jet printing. Further, in phase change ink jet printers wherein the ink droplets are applied directly onto the final recording substrate (for example, paper, transparency material, and the like), the droplets solidify immediately upon contact with the substrate, so that migration of ink along the printing medium is prevented and image quality is improved.
Ink jet printing systems generally are of two types: continuous stream and drop-on-demand, as described in U.S. Pat. No. 6,547,380. The entire disclosures of U.S. Pat. Nos. 5,195,430 and 6,547,380 are totally incorporated herein by reference.
There are at least three types of drop-on-demand ink jet systems. One type of drop-on-demand system is a piezoelectric device that has as its major components an ink filled channel or passageway having a nozzle on one end and a piezoelectric transducer near the other end to produce pressure pulses. Another type of drop-on-demand system is known as acoustic ink printing. Still another type of drop-on-demand system is known as thermal ink jet, or bubble jet, and produces high velocity droplets.
In general, phase change inks are in the solid phase at, for example, ambient or room temperature, such as about 20° C. to about 25° C., but exist in the liquid phase at the elevated operating temperature of an ink jet printing device. At the jet operating temperature, the ink is molten and droplets of liquid ink are ejected from the printing device.
In a typical design of a piezoelectric ink jet device utilizing phase change inks printing directly on a substrate or on an intermediate transfer member, such as the ones described in U.S. Pat. Nos. 5,372,852; 7,063,410; and 7,448,719 the disclosures of which are hereby incorporated by reference in their entireties. At the jet operating temperature, droplets of liquid ink are ejected from the printing device and, when the ink droplets contact the surface of the recording substrate, either directly or via an intermediate heated transfer belt or drum, they rapidly solidify to form a predetermined pattern of solidified ink drops. This approach simplifies the printhead design, and the small movements ensure good droplet registration and allows for printing directly on a substrate or on an intermediate transfer member.
Phase change inks typically used with ink jet printers have a wax based ink vehicle, for example, a crystalline wax. Crystalline waxes and other functionalized wax components enable the sharp melting of the ink and narrow phase-change transitions from the molten liquid state to the solid state. The wax components also reduce the coefficient of friction of the printed image, which aids the automated feeding of printed documents across the glass platen and other subsystems of the printer. Such ink jet inks may provide vivid color images.
In typical systems, these crystalline wax inks partially cool on an intermediate transfer member and are then pressed into the image receiving medium such as paper. Transfuse action spreads the image droplet, providing a richer color and lower pile height. The low flow of the solid ink also prevents show through on the paper.
However, the use of crystalline waxes can pose some limitations on the printed image. Conventional crystalline waxes are non-polar aliphatic hydrocarbon polymers and molecules, which are bound together by weak van der Waals forces. Such waxes typically have poor adhesion to paper substrates because there is low affinity for the higher polarity paper substrate. This mismatch of intermolecular forces and polarity between ink and substrate can make the wax-based phase change prints vulnerable to mechanical damage, such as poor scratch-resistance and poor image robustness. Other disadvantages one may encounter with the properties of non-polar wax-based ink components may include: (1) ink brittleness, which in conjunction with poor substrate adhesion, can lead to fissures and ink cracking from folds; (2) large ink volume contraction (or ink shrinkage) upon cooling molten ink to the solid form, which introduces air into the printhead and can lead to weak or missing jets; and (3) the need for custom-designed hydrophobic colorants (dyes or pigments) and ink additives, which are very costly compared to other commercially available colorants ink additives, so that good solubility or dispersability in the non-polar ink vehicle and long-term thermal stability is ensured. There is consequently a need for new phase change ink compositions having higher polarity than wax-based inks and that have good affinity for a wide variety of paper substrates and also with typical commercially available colorants and ink additives. There is furthermore a need to such new ink compositions to have improved image robustness on paper substrates compared with wax-based phase change inks.
Oxazolines are a promising class of heterocyclic compounds, which have been previously reported for medical, pharmaceutical and veterinary uses, and also as additives in personal care and consumer product formulations, such as shampoos, detergents and the like, and in oleaginous compositions such as mechanical lubricating oils and as oil and sludge dispersants. Oxazolines may be prepared efficiently in one or more reaction steps from simple starting materials, which are typically an organic carboxylic acid and a primary amino alcohol. Detailed reviews of the chemistry of oxazoles and oxazoline compounds are known, as illustrated by R.H Wiley and L. L. Bennett in Chemical Reviews, volume 44, pages 447 to 476 (1949), and also extensively described by J. W. Cornforth in Heterocyclic Compound, 1957, chapter 5, pages 300-417, the disclosures of which are totally incorporated herein by reference in their entireties. Furthermore, oxazoline derivatives being the major product from the reaction of an organic acid and amino alcohol is also known, such as disclosed by A. I. Meyers and D. L. Temple in the Journal of the Chemical Society, volume 92, page 6644 (1970), the disclosure of which is totally incorporated herein by reference.
In European Journal of Medicinal Chemistry 45, (2010), 1703-1716, Garrett C. Moraski et al. describes low toxicity anti-tuberculosis agents derived from o-hydroxy phenyl-oxazoline and o-hydroxy phenyl-oxazole benzyl esters (illustrated below).

In U.S. Pat. Nos. 3,235,557 and 3,308,024, L. S. Wiggins and coworkers (assigned to Aspro-Nicholas Ltd.) describe 5,5-bis(hydroxymethyl) substituted halo-, trifluoromethyl, or o-hydroxy-phenyloxazoline compounds and their salts which provide tranquilization and anti-convulsant for animals. (illustrated below).

In U.S. Pat. No. 4,169,836, J. Ryer et al. (Exxon Research and Engineering Co.) discloses mono-oxazoline and bis-oxazoline compounds as in Formula (A) prepared from alkenyl succinic anhydrides having at least 8 carbons in said alkenyl group, which is reacted with 1 to maximum of 2 mole equivalents of a 2,2-disubstituted-2-amino-1-alkanols, wherein the latter has 2 to 3 hydroxy groups and containing 4 to 8 carbons represented by the formula (B), wherein X is an hydroxyalkyl group such as —(CH2)nOH with n being from 1 to 3. The oxazoline compounds are disclosed to have use as additives for oil-containing compositions such as dispersants for oil sludges and oil lubricants, as well as anti-corrosion agents in gasoline. In a related disclosure, U.S. Pat. No. 4,153,566 to J. Ryer et al. (Exxon Research and Engineering Co.) describes lubricating oil compositions comprising oxazoline reaction products derived from C4-C10 mono-unsaturated dicarboxylic acid derivatives.
Monomeric oxazolines have been developed as the phase-change ink components for the Acoustic Ink Printing (AIP) technology of 1990's, as in U.S. Pat. Nos. 5,817,169 and 5,698,017. The entire disclosures of U.S. Pat. Nos. 5,817,169 and 5,698,017 are totally incorporated herein by reference. For example, U.S. Pat. No. 5,698,017 to Sacripante et al. discloses an ink composition consisting of a colorant, a vehicle component and optionally an amide or an amino ester, and which vehicle consists essentially of the condensation product of an organic acid and an amino alcohol, and which product consists essentially of an oxazoline or benzoxazoline wherein the oxazoline or benzoxazoline are represented by the following general formulas:
wherein R1 is an alkyl group of from about 1 to about 55 carbon atoms, R2, R3, R4 and R5 are alkyl, an alkyl alcohol or an alkyl ester, each alkyl containing from about 1 to about 55 carbon atoms; and U.S. Pat. No. 5,817,169 to Sacripante et al. discloses an ink composition comprised of a colorant and a vehicle component, and which vehicle component is comprised of the condensation product of an organic acid and an amino alcohol, and a mixture of an amide and an amino ester, and wherein said mixture contains from about 1 to about 99 parts of said amide and from about 99 parts to about 1 part of said ester.
While the known compositions and processes may be suitable for their intended purposes, a need remains for phase change ink compositions suitable for ink jet printing under a variety of conditions, such as direct-to-paper (DTP) printing conditions. In addition, there is a need for phase change ink compositions that are compatible with a wide variety of papers that generate high quality images on a wide variety of papers at low cost. Further, there is a need for phase change ink compositions that exhibit minimal high volume contraction (or shrinkage) upon cooling the ink to solid form, which would minimize the introduction of air into the printhead and weak or missing jets when printing. These and other needs and advantages can be achievable with the compositions comprising substituted oxazoline compounds and/or substituted oxazoline derivatives of the present disclosure.